Tuning device with clutch operated contact plate means



March 23, 1965 WEBB ETAL 3,175,053

TUNING DEVICE WITH CLUTCH OPERATED CONTACT PLATE MEANS 2 Sheets-Sheet 1Original Filed April 26, 1960 JNVENTORS. DONALD 6. WEBB [ZOO/V 0. ALDAEDMarch 23, 1965 D. E. WEBB ETAL 3,175,053

TUNING DEVICE WITH CLUTCH OPERATED CONTACT PLATE MEANS Original FiledApril 26, 1960 2 Sheets-Sheet 2 INVENTORS. DONALD E. WEBB [ZOO/V .0. AZDPED MBA/E Y United States. Patent I 3,175,053 TUNING DEVICE WITH CLUTCHOPERATED CONTACT PLATE MEANS Donald E. Webb, deceased, late ofIndianapolis, Ind., by Mrs. Donald E. Webb, administratrix, Casper,Wyo., and Eldon D. Aldred, lndianapolis, Ind., assignors to P. R.Mallory & Co., Inc., Indianapolis, Ind., 21 corporation of DelawareOriginal application Apr. 26, 1960, Ser. No. 24,854, now Patent No.3,013,152, dated Dec. 12, 1961. Divided and this application Sept. 19,1961, Ser. No. 141,560 7 Claims. (Cl. 200-11) This is a division ofapplication Serial No. 24,854, now Patent No. 3,013,152, filed April 26,1960.

This invention relates generally to electro-magnetic energy tuningdevices operative over a wide band of high frequency ranges and hasspecific application to such devices including means and methods forinductively tuning high frequency apparatus, and the like.

The :present invention relates to multi-sectioned tuning devicesincluding continuously variable tuning coils of the inductance type inwhich the improved construction allows for exceeding diminution of thevolume usually required. For example, the present tuning device can bemade as much as seven times smaller than the normal tuning mechanism,while maintaining Q ratings far in excess of the necessary minimumspecifications.

Each of the inductive tuning elements used in the assembly, or receiver,or transmitter tuner front end, as the multi-sectioned device is called,is adapted to display a linear relationship between frequency androtation so that a conventional dial may be replaced by a numericalcounter or Wheel type index.

The tuner is constructed to linearly cover a range of 30-76 Inc. with aband-switch or break at 53 mc. The invention includes a printed circuitslide switch which is adapted to band-switch each of a number of printedcircuit type modular RF and antenna boards which are assembled to form atuning head or front end. A common shaft actuates each of theband-switches.

The invention is therefore a considerable advance in the construction ofminiature electronic assemblies, and moreover, the individual electronicassemblies are so constructed that they are easily demountable andreadily removable and serviceable from the tuning head or main assembly,itself.

' The tendency toward miniaturization of electronic elements such astube, resistors, coils, capacitors, has made it necessary 'to reduce theover-all dimensions of tuning and switching components to cope with thisreduction in .size; In addition to this, since this compactness ofconstruction brings its own problems of maintenance and re- ,pair,accessibility of all portions of the tuner for quick repair orreplacement becomes a must. The construction now offered permits thefulfillment of all these criteria by providing an assembly of easilyremovable modular .boards upon which the components may be arranged inconjunction with spiral inductors in ganged relationship to a slidablemultiple circuit; switching mechanism for allowing the discriminatinguse of 'multi-band tuning.

It is therefore an object of" the presentinvention to provide aminiature inductive tuning assembly having improved constructionalfeatures of band-switching and which has improved frequency versusrotational characteristics.

Another object of the present invention is to provide an improved spiralwound tuning device adapted for inductive tuning in a series of resonantcircuits giving improved linear tuning characteristics.

Another object of the present invention isthe provision of a miniatureinductive tuning assembly made up of a desired number of sections,furnishing shielding between plurality of readily removablesub-assemblies, each of which is composed of units slideably receivedwithin the sub-assembly.

Another object of the present invention is to provide a band changingswitch of improved and novel construction used in a linear tuningcharacteristic spiral tuner which will give predetermined rotationalpositional accuracy during tuning.

Yet another object of the present invention is to provide an improvedspiral wound tuning device adapted for inductively tuning resonantcircuits of multi-bands of very high frequency electrical signals.

Still another object of the present invention is the provision ofinductive tuning devices-having new and improved coil form assembly towhich an improved switch member and associated control elements areconnected so as to particularly adapt the use of the tuning device forcompact arrangement.

Although the novel features which are characteristics of the inventionare set forth more in detail in the claims appended hereto, the natureand scope of the invention may be better understood by reference to thefollowing description taken in connection with the accompanying drawingsforming a part thereof and in which a specific embodiment has been setforth for purposes of illustration.

In the drawings,

FIG. 1 is a perspective, partly broken away section view of anembodiment of the invention of a new inductive tuning assembly showingthe arrangement of the inductive spiral ribbon in relation to anassociated component carrying panel and slider switch mechanism fordetermining the separate frequency bands of the tuner.

FIG. 2 is a partial front elevational view of the actuator and switchingslide of the switching mechanism for determining the separate frequencybands of the tuner.

FIG. 3 is an exploded perspective view of the switch slide mechanism ofthe invention in conjunction with a portion of the printed circuit.

FIG. 4 is a vertical sectionalized view of FIG. 1 taken along line 44thereof, and FIG. 5 is a longitudinalcrosssectional view of the tunerassembly of an embodiment of the invention.

In the following description, certain specific terms are used forconvenience in referring to the various details of the invention. Theseterms are to be interpreted, however, in accordance with the state ofthe art.

Generally speaking, the present invention relates to a continuouslyvariable tuning device of the inductance type. In accordance with theinvention, a spiral wound conductor having a ribbon configuration hasone of its edges vertically embedded in an insulative base, such asplastic, and held in an upright manner therein. The multiple turns ofthe conductor are spirally wound within each other and fixedly retainedin the insulator base. A hinged contact arm having a wiper is thenallowed to ride on the outer edge of the conductor in an essentiallyexpanding manner dependent upon the angular relationship of the hinge totheconductor.

The spiral inductor has been constructed to obtain a linear frequencyversus rotation characteristicg- This is made by winding a silverribbon, starting at some distance from the center of the spiral, with anever increasing radius. After approximately 5 to 8 turns are wound, thesilver ribbon is formed into an exponential curve 'to a point which willbe tangential to-the frame or housing of the tuner. The spiral isinserted into grooves or is moldedinto a dielectric material base. 'Sucha base possesses a low dissipation factor and preferably a lowdielectric constant. The completed tuning device is then formed byhousing the spiral into a metallic frame of the desired number ofsections, furnishing shielding between the sections and then supplyingelectrostatic shielding.

The great need for minimizing unwanted capacitances and inductanceswhich could unbalance the linear characteristics sought, and thenecessity of being able to assemble and disassemble the electroniccomponents associated with the tuner, per se, has been achiever in theas.- sembly by the use of novel vertical slider component carryingpanels. These panels move into intimate vertical engagement with springslider tuner terminals and are removable without disturbing the actualspirals of the tuners.

The spiral of each of the tuner elements has its exponentially curvedand electrically connected to a shield. A second contact is created byattaching a lead to the center of the spiral and bringing this lead tothe desired location in or on the housing. Tuning is accomplished, asstated, by moving the contactor arm along the convoluted spiral. Thecontactor arm is then, in fact, electrically connected to the housingcausing the inductance to vary between the center of the spiral and thecontact point as the contactor is rotated.

Incorporated in the tuning mechanism is a printed circuit slide switchwhich functions to band-switch each of a number of printed circuit typemodular RF and antenna boards which are assembled to form a tuning head.A common shaft actuates each of the separate band-switches. Since it isdesired that each of the modular boards may be removed withoutdisturbing the bandswitch shaft, the switch is integrally related toeach of the separate boards. The switch is capable of switching anydesired number of circuits operative at given frequencies.

Referring more particularly to the drawings, there is shown in FIGS. 1and 2, a front end section, or multiple tuning section constructed toaccept very high frequency electrical energy signals. This front endincludes (a) the switch slide 11, (b) the printed circuit boards 14, (c)tuning coil 12 and mounting boards 13, (d) the contacts 15 forconnecting the printed circuit to the tuning coils, (e) parent board 17,(f) parent board connector means 18 and the casing 19 including top (notshown), bottom, 20 and side walls 21 and shielding partitions 22.

It is desirable that since the tuner is to be used in communicationequipment having dialing or counting indicia, that the spacing betweenindices be uniform. This would make the tuner linear. This isaccomplished, as stated above, by utilizing a termination lead of anexponential nature. It possesses a spacing between itself and theoutermost' turn of the spiral which is ever-increasing. The length is inthe order of one-half of a turn around the spiral. The spiral,constructed in this manner; i.e., a planar spiral with an exponentiallead going to a point on a totally inductively shielded case, willpossess a charplates for the spirals are of a minimum thickness capableof holding the ribbon inductances in place within the grooves formedtherein.

The rotors or contactor arms 23 are connected to a shaft 24 whichextends into each of the sections. The contacts 25 of the arms ride onthe outside face ofthe spiral. Terminals fer the spirals are created bybringing one lead from the spiral to a desired point on the case andanother lead from the center of the spiral to an adjacent point. Theseleads are insulated from each other and from the case at all points.

As shown in the figures, the tuner casing has been constructed to avoidneedless stray capacitances and inductances. At one side, usingapproximately one-half of the allotted volume of the casing the tuningcoils are arranged on vertical insulated panels. At the side thereof isa metal shield 27 having approximately the same height as the coilsupports. This shield separates the tuning elements per so, from aparent component board 17 which includes terminal connector stripshaving a plurality of spring connectors 20 thereon, as well as carryingon its top and bottom, electrical components such as resistors, diodes,inductors, and capacitors. Both the tuner coils and the componentcarrying and connector terminal board are fixedly retained within thetuning casmg.

The tuning casing is constructed to receive sliding component carrying,printed circuit panels into intimate engagement with the tuner spiralsand the external fixed parent contact boards. Each panel is of uniqueconstruction so that it can be vertically mounted adjacent the tunerspirals to be connected therewith, as well as carry- 7 ing a sliderswitch 11 adapted to be placed in cooperative acteristic inductancewhich is mostly increasing or de- 7 creasing when the contactor armrides along the face of the spiral.

This result can be explained by electromagnetic field considerations.Normally a spiral is ended at a determined point. This causes the spiralto have n turns just beforethe point of termination or (n-1) turnsimmediately beyond the point of termination. This fact causes an abruptchange in the geometry of the electromagnetic field which produces theinductance. By tapering the termination in an exponential fashion, thisabrupt change is avoided. By terminating the lead at a point on atotally enclosed conducting casing, a unipotential field is setup aroundthe spiral which further enhances this gentle changing of the spiralfield geometry.

The casing 19 is made of silver or silver clad copper by bending twosides and two ends at right angles. Shields 22 are inserted into thesides parallel to the ends so as to form equally spaced cavities.Blocks. or plates 13 of extremely high quality dielectric material havethe inductance spirals 12 mounted in grooves formed in one face thereofor imbedded therein. The dimensions of the blocks are such that theinductance spirals are located in the center of each of the cavities orsections. The

relationship with each of several similar panels included by theseparate tuning sections. This slider switch will move in relationshipto printed circuit terminals and conductors to switch electromagneticenergy into several frequency bands determined by the circuiting on thepanel which will place determined reactances into engagement with therotatable tuner spiral. A portion 31 of the printed circuit boardextends downwardly at right angles to the main section 32 of the boardand carries end printed conductor terminals 33 which are gripped by thespring terminals 30 on the fixed parent board 17. The configuration ofthe printed circuit board takes on an inverted L-shaped form. At the topof the sides of the casing two guide slots 40 are formed into which a T-shaped collar 41 integrally formed to the printed circuit boards areinserted. When the boards are vertically inserted into the slots andstruck out guide ears (FIG. 5), the printed terminals of the mainsection of the board slide into connection with the mating springterminals at the tuner section and those of the parent panel. section(FIG. 4). The engagement of all terminals is extremely tight and allowsfor good electrical conductivity between sections of the printed circuitboard, the inductance spiral, and the parent component carrying board.

As stated, each printed circuit board is of an inverted L-shapedconfiguration and carries a slider switch assembly (-FIG. 2) thereonwhich is adapted to be actuated between printed circuit terminalsdefining the frequency bands covered by the tuner. Each of the switchesis ganged and actuated simultaneously with corresponding switches on theother circuit boards by means of a shaft which ,passes through an arcedcut-out 51 formed in the board.

The sliding switch 1 1 consists of a thin rectangular flat insulatorplate 52 which is attached to each printed circuit board by means ofintegrally formed idler or guide pins 53 fitted into guide slots 54 cutout of opposing ends of the plate. Each printed circuit board has itsswitchterminals printed thereon. Adjacent thereto on one flat side ofthe switch plate are the three finger switch contacts 63 formed ofarcuately shaped fiat spring ribbons staked to the plate. The actuator,shaft '50 has a U-shaped dual pronged clutching member 65 which acceptsan integrally formed post 67 extending horizontally out from the switchplate. This post falls Within the prongs of the clutching member to beactuated and moved upon angular rotation of the actuator. An indexingplate 70 is placed on the front wall of the casing which allows fordetenting and indexing of the switch positions.

In the construction of the tuner, the desirability of readyaccessibility of all portions of the tuner assembly for quick repair orreplacement has been achieved. The tuning shaft 24 is completelyseparated from the actuator 65 of the sliding band switch. The actuator65 of the sliding band switch, by its construction remains in placewhile the printed circuit boards can be removed by simply lifting theprinted boards upwardly away from the shaft while it is in the unlockedposition. Moreover each of the boards are vertically aligned to oneanother by means of the guide slots and ears placed in the walls of thetuner casing.

The present invention of the tuner assembly with its band switchingfeatures and demountable circuit boards is merely illustrative and notexhaustive in scope and since many Widely different embodiments of theinvention may be made without departing from the scope thereof. It isintended that all matter contained in the above description and shown inthe accompanying drawing shall be interpreted as illustrative and not ina limiting sense.

What is claimed is:

1. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising: a printed circuit board means; aplurality of printed terminal means printed on said printed circuitboard means; a plurality of guide pin means fixedly coupled to andextending outwardly from said printed circuit board means; a rectangularshaped insulator plate means having guide slot means in opposing ends ofsaid plate means, said guide slot means interfitting with said guide pinmeans maintaining said plate means in spaced parallel relationship withsaid printed circuit means; a post means extending outwardly from saidplate means; a plurality of contact means cooperatively associated withsaid plate means, said contact means mounted to engage said printedterminal means; and an actuator shaft means having a clutching means forinterfitting with said post means, arcuate displacement of said actuatorshaft causing said clutching means to engage said post means to slidablydisplace said contact means in a lateral direction thereby breakingengagement with said two of said plurality of printed terminal means andmaking engagement with other of said plurality of said printed terminalmeans.

2. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising; a printed circuit board means,said printed circuit board removably jointed to spiral tunable elements;a plurality of printed terminal means printed on said printed circuitboard means, said plurality of printed terminal means coupled toelectrical components; a plurality of guide pin means fixedly coupled toand extending outwardly from said printed circuit board means; arectangular shaped insulator plate means having guide slot means inopposing ends of said plate means, said guide slot means interfittingwith said guide pin means maintaining said plate means in spacedparallel relationship with said printed circuit means; a post meansextending outwardly from said plate means; a plurality of contact meanscooperatively associated with said plate means, said contact meansmounted to engage said printed terminal means; an actuator shaft meanshaving a demountably coupled clutching means for interfitting with saidpost means, arcuate displacement of said actuator shaft causing saidclutching means to engage said post means to slidably displace saidcontact means in a lateral direction in a plane parallel to said printedcircuit board means thereby breaking engagement with said two of saidplurality of printed terminal means and making engagement with other ofsaid plurality of said printed terminal means; and an indexing meanscoupled to said actuator shaft means, said indexing means for indexingpositions of said contact means on said printed circuit board means.

3. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising: a printed circuit board means; aplurality of printed terminal means printed on said printed circuitboard means; a plurality of guide pin means fixedly coupled to andextending outwardly from said printed circuit board means; a rectangularshaped insulator plate means having guide slot means in opposing ends ofsaid plate means, said guide slot means interfitting with said guide pinmeans maintaining said plate means in spaced parallel relationship withsaid printed circuit means; a post means integrally formed with andextending outwardly from said plate means; a plurality of arcuatelyformed three fingered contact means staked to said plate means, saidcon-tact means mounted to engage at least two of said printed terminalmeans; and an actuator shaft means having a U-shaped clutching means forinterfitting with said integrally formed post means, arcuatedisplacement of said actuator shaft causing said U-shaped clutchingmeans to engage said post means to slidably displace said contact meansin a lateral direction thereby breaking engagement with said two of saidplurality of printed terminal means and making engagement with other ofsaid plurality of said printed terminal means.

4. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising: a printed circuit board means; aplurality of printed terminal means printed on said printed circuitboard means; a plurality of guide pin means fixedly coupled to andextending outwardly from said printed circuit board means; a rectangularshaped insulator plate means having guide slot means in opposing ends ofsaid plate means, said guide slot means interfitting with said guide pinmeans maintaining said plate means in spaced parallel relationship withsaid printed circuit means; a post means integrally formed with andextending outwardly from said plate means; a plurality of arcuatelyformed three fingered contact means staked to said plate means, saidcontact means mounted to engage at least two of said printed terminalmeans; an actuator shaft means having a U- shaped clutching means forinterfitting with said integrally formed post means, arcuatedisplacement of said actuator shaft causing said U-shaped clutchingmeans to engage said post means to slidably displace said contact meansin a lateral direction thereby breaking engagement with said two of saidplurality of printed terminal means and making engagement with other ofsaid plurality of said printed terminal means; and an indexing meanscoupled to said actuator shaft means, said indexing means for indexingpositions of said fingered contacts on said printed circuit board means.

5. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising; a printed circuit board means,said printed circuit board removably joined to spiral tunable elements;a plurality of printed terminal means printed on said printed circuitboard means, said plurality of printed terminal means coupled toelectrical components; a plurality of guide pin means fixedly coupled toand extending outwardly from said printed circuit board means; arectangular shaped insulator plate means having guide slot means inopposing ends of said plate means, said guide slot means interfittingwith said guide pin means maintaining said plate means in spacedparallel relationship with said printed circuit means; a post meansintegrally formed with and extending outwardly from said plate means; aplurality of arcuately formed three fingered contact means staked tosaid plate means, said contact means mounted to engage at least two ofsaid printed terminal means; and an actuator shaft means having ademountably coupled U-shaped clutching means for interfitting with saidintegrally formed post means, arcuate displacement of said actuatorshaft causing said U-shaped clutching means to engage said post means toslidably displace said contact means in a lateral direction therebybreaking engagement with said twoof said plurality of printed terminalmeans and making engagement with other of said plurality of said printedterminal means.

6. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising: a printed circuit board means,said printed circuit board removably joined to spiral tunable elements;a plurality of printed terminal means printed on said printed circuitboard means, said plurality of printed terminal means coupled toelectrical components; a plurality of guide pin means fixedly coupled toand extending outwardly from said printed circuit board means; arectangular shaped insulator plate means having guide slot means inopposing ends of said plate means, said guide slot means interfittingwith said guide pin means maintaining said plate means in spacedparallel relationship with said printed circuit means; a post meansintegrally formed with and extending outwardly from said plate means; aplurality of arcuately formed three fingered resilient contact meansstaked to said plate means, said contact means mounted to engage atleast two of said printed terminal means; an actuator shaft means havinga demountably coupled U-shaped clutching means for interfitting withsaid integrally formed post means, arcuate displacement of said actuatorshaft causing said U-shaped clutching means to engage said post means toslidably displace said contact means in a lateral direction therebybreaking engagement with said two of said plurality of printed terminalmeans and making engagement with other of said plurality of said printedterminal means; and an indexing means coupled to said actuator shaftmeans, said indexing means for indexing positions of said fingeredresilient contacts on said printed circuit board means.

7. A printed circuit slide switch means for band switching in a highfrequency tuning assembly comprising: a printed circuit board means,said printed circuit board removably joined to spiral tunable elements;a plurality of printed terminal means printed on said printed circuitboard means, said plurality of printed terminal means coupled toelectrical components; a plurality of guide pin means fixedly coupled toand extending outwardly from said printed circuit board means; arectangular shaped insulator plate means having guide slot means inopposing ends of said plate means, said guide slot means interfittingwith said guide pin meansomaintaining said plate means in spacedparallel relationship with said printed circuit means; a post meansintegrally formed with and extending outwardly from said plate means; aplurality of arcuately formed three fingered resilient contact meansstaked to said plate means, said contact means mounted to engage atleast two of said printed terminal means; an actuator shaft means havinga demountably coupled U-shaped clutching means for interfitting withsaid integrally formed post means, arcuate displacement of said actuatorshaft causing said U-shaped clutching means to engage said post means toslidably displace said contact means in a lateral direction in a planeparallel to said printed circuit board means thereby breaking engagementwith said two of said plurality of printed terminal means and makingengagement with other of said plurality of said printed terminal means.

References Cited by the Examiner UNITED STATES PATENTS 1,949,568 3/34Gotham ZOO-16 XR 2,070,599 2/37 Hubbell et a1. 200-87 2,745,915 5/56Pantages 200-l1 2,748,286 5/56 Bussard 334-3 2,942,073 6/60 Barr 20016XR 3,013,152 12/61 Webb et al.

3,025,361 3/62 Hartsock et al. 200-11 3,042,763 7/62 Strathearn ZOO-11XR 3,119,905 1/64 Nicolaus 20011 BERNARD A. GILHEANY, Primary Examiner.

1. A PRINTED CIRCUIT SLIDE SWITCH MEANS FOR BAND SWITCHING IN A HIGHFREQUENCY TUNING ASSEMBLY COMPRISING: A PRINTED CIRCUIT BOARD MEANS; APLURALITY OF PRINTED TERMINAL MEANS PRINTED ON SAID PRINTED CIRCUITBOARD MEANS; A PLURALITY OF GUIDE PIN MEANS FIXEDLY COUPLED TO ANDEXTENDING OUTWARDLY FROM SAID PRINTED CIRCUIT BOARD MEANS; A RECTANGULARSHAPED INSULATOR PLATE MEANS HAVING GUIDE SLOT MEANS IN OPPOSING ENDS OFSAID PLATE MEANS, SAID GUIDE SLOT MEANS INTERFITTING WITH SAID GUIDE PINMEANS MAINTAINING SAID PLATE MEANS IN SPACED PARALLEL RELATIONSHIP WITHSAID PRINTED CIRCUIT MEANS; A POST MEANS EXTENDING OUTWARDLY FROM SAIDPLATE MEANS; A PLURALITY OF CONTACT MEANS COOPERATIVELY ASSOCIATED WITHSAID PLATE MEANS, SAID CONTACT MEANS MOUNTED TO ENGAGE SAID PRINTEDTERMINAL MEANS; AND AN ACTUATOR SHAFT MEANS HAVING A CLUTCHING MEANS FORINTERFITTING WITH SAID POST MEANS, ARCUATE DISPLACEMENT OF SAID ACTUATORSHAFT CAUSING SAIDD CLUTCHING MEANS TO ENGAGE SAID POST MEANS TOSLIDABLY DISPLACE SAID CONTACT MEANS IN A LATERAL DIRECTION THEREBYBREAKING ENGAGEMENT WITH SAID TWO OF SAID PLURALITY OF PRINTED TERMINALMEANS AND MAKING ENGAGEMENT WITH OTHER OF SAID PLURALITY OF SAID PRINTEDTERMINAL MEANS.